1. Field of the Invention
The present invention relates to surgical suture devices and, more particularly, to suture devices made of bioabsorbable materials particularly useful in endoscopic surgery and methods of suturing using such suture devices.
2. Discussion of the Prior Art
Suturing of bodily tissue is a time consuming part of most surgical procedures including both open surgery and endoscopic or closed surgery. By open surgery is meant surgery wherein the surgeon gains access to the surgical site via a relatively large incision, and by endoscopic surgery is meant surgery wherein the surgeon gains access to the surgical site via one or more portals through which endoscopes are introduced to view the surgical site and through which instruments, such as forceps, cutters, applicators and the like, are introduced to the surgical site. There are many common endoscopic surgical procedures, including arthroscopy, laparascopy (pelviscopy), gastroentroscopy and laryngobronchoscopy, for example. In the past, suturing has been accomplished with the use of a sharp metal suture needle attached to the end of a length of suture material, the suture needle being caused to penetrate and pass through the tissue pulling the suture material through the tissue. Once the suture material has been pulled through the tissue, the surgeon ties a knot in the suture material, the knotting procedure allowing the surgeon to adjust the tension on the suture material to accommodate the particular tissue being sutured and control approximation, occlusion, attachment or other conditions of the tissue. The ability to control tension is extremely important to the surgeon regardless of the type of surgical procedure being performed; however, knotting of the suture material is time consuming and tedious work, particularly in microsurgery and endoscopic surgery. That is, in microsurgery suturing is necessarily time consuming due to the small size of the suture needle and the suture material and the concomitant difficult manipulation required to pass the suture needle through the tissue and to tie a knot in the suture material. With respect to endoscopic surgery, suturing and tying knots represents an even more time consuming procedure due to the difficult maneuvers required. Accordingly, while endoscopic surgery would be preferred for most procedures, the advantages are often outweighed by the disadvantages caused by the length of time required to complete the endoscopic surgical procedure, which time is greatly extended due to the time required for suturing. Another disadvantage of suturing with a metal suture needle and suture material during endoscopic surgery is that the suture needle is difficult to hold and manipulate and can be easily dropped. Should the suture needle be dropped, open surgery with its attendant disadvantages must be performed to find and remove the needle.
There have been many attempts to provide devices to take the place of conventional suturing with a suture needle and a length of suture material; however, such prior art devices have essentially been staples, clips, clamps or other fasteners not providing the adjustable tension obtained by the surgeon while knotting a length of suture material. U.S. Pat. Nos. 3,827,277 to Weston, 4,060,089 to Noiles, 4,490,326 to Beroff et al, 4,513,746 to Aranyi et al, 4,532,926 to O'Holla, 4,548,202 to Duncan, 4,573,469 to Golden, No. 4,590,937 to Deniega, 4,595,007 to Meride, 4,602,634 to Barkley, 4,646,741 to Smith, 4,671,280 to Dorband et al, 4,719,917 to Barrows et al and 4,741,337 to Smith et al are representative of such prior art devices for use in place of conventional suturing. Many of these prior art devices are made of bioabsorbable materials such that the devices are absorbed over time into the bodily tissue and do not have to be removed after the bodily tissue has healed.
There exist many compositions useful as bioabsorbable materials, as represented by the above patents and by U.S. Pat. Nos. 3,739,773 to Schmitt et al, 3,797,499 to Schneider, 4,141,087 to Shalaby et al, 4,300,565, 4,523,591 to Kaplan et al and 4,649,921 to Koelmel et al which discuss characteristics of various bioabsorbable materials and medical devices desirably manufactured of such materials, such medical devices being of a type designed to be engaged in, embedded in or otherwise attached to various types of bodily tissue, such as bone, muscle, organs, skin and other soft tissue, to remain in place in the tissue until the device is absorbed into the body.
U.S. Pat. No. 3,570,497 to Lemole discloses a suture device formed of a needle with a piercing point extending from a latch cord carrying notches designed to pass through a latch collar, the latch cord being resilient to be curved upon itself to form a suture stitch without requiring tying of a knot; however, the latching function does not provide the same feel and tension control as knotting a length of suture material. U.S. Pat. No. 4,548,202 to Duncan uses similar structure in a tissue fastener device in that serrations or angled barbs are provided on spaced legs passing through tissue to be engaged by an apertured receiver or a flexible filament mesh. U.S. Pat. No. 3,123,077 to Alcamo discloses a surgical suture carrying raised projections or depressions or teeth such as barbs or spicules to snag or penetrate tissue to effectively hold a sewed incision or wound.
Endoscopic surgery is preferred over open surgery due to the greatly reduced trauma and wound healing time for the patient and due to concomitant cost savings associated with shorter hospital stays and performing surgery without general anesthesia and in non-hospital or out-patient surgery sites. Accordingly, there has been much effort spent to develop techniques for facilitating the suturing normally performed by use of a metal suture needle and a length of suture material. Alternative techniques proposed have included electrical coagulation, mechanical devices such as clips, clamps and staples, and lasers; however, no well accepted alternative has yet been found in that suturing and tying are essential and vital parts of most surgical procedures. That is, to date the proposed alternatives have had disadvantages, including increased risk to the patient, while not providing the surgeon with the advantages of suturing and tying and not being useful in a wide range of procedures to allow expansion of the areas in which endoscopic surgery can be effectively performed. Thus, there is a great need for suture devices, particularly useful in endoscopic surgery, that allow surgeons to suture and tie knots in a manner with which they are familiar without undue concern as to the loss of the suture needle and further for suture devices that allow controlled approximation of tissue and tying to produce controlled tension.